pidgin-sipe says messages are not delivered during group chat because it thinks no one is online

Whenever I'm in a group chat with other people in my company, every time I type in a message, I get this response:

    This message was not delivered to sip:<person> because one or more recipients are offline:

I get one of these lines for each other person in the chat, listing that person's email address. I know the message is bogus, because everyone else in the chat does receive my messages.

This may be the same bug as http://sourceforge.net/p/sipe/bugs/151/

However, that bug is supposedly fixed. Perhaps updating Ubuntu 14.04 to pidgin-sipe 1.20.1 will fix this? I tried compiling 1.20.1, but it complained about missing dependencies, and I didn't know what other packages to install

 configure: error: nss, mozilla-nss, microb-engine-nss or libcrypto package is required

$ lsb_release -rd
Description: Ubuntu 14.04.3 LTS
Release: 14.04

$ apt-cache policy pidgin-sipe
pidgin-sipe:
  Installed: 1.17.3-1
  Candidate: 1.17.3-1
  Version table:
 *** 1.17.3-1 0
        500 https://ausimg01.qualcomm.com/shire/Ubuntu/media-UbuntuLandscape-14.04-amd64/ trusty/universe amd64 Packages
        500 http://archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
        100 /var/lib/dpkg/status